Four Card Feature Section

I think the preview looks squashed because you used vh? As far as I know, what that would do is fill the height of the viewport, not more. Frontend Mentor took the screenshot of their 'preview', which has a shrunken height due to the header and stuff. Since you used vh, if you shrink the browser in height it will try to fill only that space(i.e, shrink your page in height). It's almost like it's height responsive. That may cause a lot of issues. This is how it will look on a tablet: https://drive.google.com/file/d/1_PgUXCWEJDwRw6PZBDU1t93jaSpPyLtj/view?usp=sharing

I suggest you use '%' instead of vw and vh, and 'rem' for font size, and 'em' for margin. They work well, since they are relative to the font size. I'm not very experienced with front end yet, but those worked well for me :)